Lasers in surgery and medicine reviewers. November 1, 1992 through October 31, 1993

Chloro-aluminum sulfonated phthalocyanine (CASPc) is a photo-chemically active dye employed in photodynamic therapy (PDT). CASPc is a potent generator of singlet oxygen when irradiated with 675 nm light and is also capable of fluorescence, allowing visualization of the dye in tissues. We devised an angiography system using CASPc fluorescence to determine its localization in experimental choroidal neovascularization in monkeys and then investigated the ability of CASPc to produce photochemical closure of neovascularization upon irradiation with 675nm laser light. Fluorescent imaging indicated that CASPc localized angio-graphically in areas of neovascularization for at least 24 hours. Irradiation with 675 nm laser light 5–30 minutes after CASPc injection produced complete closure of choroidal neovascularization with minimal damage to overlying retina. We conclude that CASPc localizes in neovascular choroidal vessels and that CASPc photodynamic therapy can produce closure of these choroidal vessels. © 1994 Wiley-Liss, Inc.     

Furosemide and acute renal failure.

High dose of intravenous furosemide (2 g/24 hr) was given to six patients with acute renal failure due to leptospirosis. The results, based on urine flow, changes in serum creatinine and creatinine clearance, were compared with a control group of eight patients with the same disease and comparable degree of renal failure. Excellent diuresis was observed following furosemide therapy but renal function and the clinical course of the disease were unaltered. The duration of renal failure was the same in both groups.     

Complications of hydrogel explants used in scleral buckling surgery

PURPOSE: To report a group of patients with symptoms of pain, strabismus, sensation of orbital fullness, and presence of a subconjunctival mass many years after successful scleral buckling surgery using hydrogel explants. DESIGN: We present an interventional consecutive case series of patients who underwent scleral buckling surgery using hydrogel explants from 4 to 14 years before onset of clinical symptoms. SETTING: This is a retrospective, multicenter clinical study. Patient population: 17 eyes of 15 patients presented with this disorder. All patients were examined; Snellen acuity, ocular motility, tonometry, slit lamp, and fundus examination were recorded. Two patients underwent either computed tomography or magnetic resonance imaging. Removal of the hydrogel explant was attempted in all patients. Removal of the buckle was technically difficult; the hydrogel material was fragile and fragmented when handled. RESULTS: All patients had prompt relief of pain and discomfort. Ocular motility and diplopia were greatly improved. Extraocular muscle surgery was not required in any case. Three eyes had intraoperative eye wall perforation. One eye developed postoperative bacterial endophthalmitis. Five eyes had recurrence of retinal detachment. One eye had additional complications of corneal edema and glaucoma. CONCLUSIONS: Patients who develop this clinical condition should be considered for removal of the hydrogel scleral buckle. Early recognition of this condition may prevent serious complications associated with delayed removal.     

Continence mechanism of the ileal neobladder in women: a urodynamics study

We undertook this study to evaluate the mechanism of continence in women who underwent modified radical cystectomy and creation of an ileal neobladder. Our surgical technique was modified in accordance with detailed anatomic dissection of female pelvises with attention to the innervation of the pelvic musculature and urethral sphincter. Ten women aged 41–71 years (mean 64.3 years) underwent nerve-sparing radical cystectomy and creation of an orthotopic neobladder with detubularized ileum. Videourodynamic evaluation was performed 6 months postoperatively to evaluate sphincteric and reservoir function. Seven of the ten patients were totally continent after the procedure, requiring no protective pad. Of these, one requires intermittent self-catheterization. Videourodynamic evaluation revealed a low-pressure reservoir with a mean capacity of 467 ml, and leakage did not occur during Valsalva maneuver. Three patients reported significant incontinence (more than one pad per day) after orthotopic reconstruction. These patients demonstrated intrinsic sphincteric deficiency with a low mean abdominal leak-point pressure of 48.3 cmH₂O. Two of these women had stress incontinence preoperatively. In conclusion, continence can be preserved in most women after modified radical cystectomy and orthotopic bladder replacement. Success results from preservation of the intrinsic sphincteric mechanism and the creation of a low-pressure, compliant reservoir. A history of stress incontinence preoperatively appears to predispose to sphincteric weakness postoperatively.     

A controlled trial of heparin therapy in the coagulation defect of paracetamol-induced hepatic necrosis

Treatment of the coagulation disturbances developing with hepatic damage following a paracetamol overdose was assessed in a controlled trial of 22 patients, one half being given heparin and fresh frozen plasma and the other fresh frozen plasma alone. No significant difference was observed either in the speed of correction of the coagulation defect or in the clinical outcome. Two-thirds of the patients had evidence of disseminated intravascular coagulation, but despite the presence of a severe coagulation defect, significant bleeding occurred in only five patients. This may be because with paracetamol-induced hepatic necrosis both the coagulation defect (and possibly other features attributable to severe hepatic insufficiency) are of shorter duration than in hepatic necrosis due to causes such as viral hepatitis in which the liver damage may be a continuing process.     

Ultrasound evaluation of the penis for assessment of impotence

Image directed Doppler ultrasonography of the cavernous arteries provides functional, quantifiable assessment of penile arterial flow during a pharmacological erection. In this respect, this modality is superior to arteriography as a means of evaluating arteriogenic impotence. Peak flow velocity, arterial dilatation, and vessel pulsation are the most reliable ultrasonic indicators of arterial health. Aberrant arterial anatomy should be noted as this may contribute significantly to total penile blood flow. A thorough understanding of erectile physiology and anatomy is necessary to properly perform and interpret Doppler ultrasound results. © 1996 John Wiley & Sons, Inc.     

Acute renal failure in obstructive jaundice in cholangiocarcinoma

This study was aimed at defining the natural history of renal failure in obstructive jaundice due to cholangiocarcinoma, which is an important health problem in northeastern Thailand. Sixty-four patients among a total of 130 patients with obstructive jaundice secondary to cholangiocarcinoma who developed acute renal failure were studied retrospectively. Analysis was made with respect to clinical features, laboratory findings, and outcome. The development of renal failure before surgery was observed in all patients. It was nonoliguric in 80% and was associated with severe jaundice, gram-negative infection (42%), hypotension (31%), hypoproteinemia (30%), hyponatremia (56%), and hypokalemia (63%). The mean duration of renal failure was 2 weeks. All patients underwent surgery for the relief of jaundice. Seventy-seven percent of the patients survived and had recovery of renal function after the relief of jaundice. Twenty-three percent of the patients died of infection. Clinical data highlight the higher serum bilirubin levels and the frequent occurrence of hyponatremia, hypokalemia, and hypotension in renal failure. Their possible roles in contributing to the development of renal failure are discussed.